On numeric keypads, such as telephone touch-tone keypads, a single key corresponds to multiple characters. For example, on a typical telephone touch-tone keypad, the "2" key corresponds to the letters "A", "B", and "C".
Many applications require a user to enter character information on a keypad. To do this, the user presses the key associated with the desired character. Since each key represents several characters, the application must determine which of these characters is intended by the user. This is often accomplished by allowing the user to iterate though the possible characters by pressing the corresponding key multiple times. For example, to enter the letter "C", the user would press the "2" key three times. To enter the letter "B", the user would press the "2" key twice. In other approaches, a special key (e.g., the "#" key) is pressed to iterate though the choices. Each time the key is pressed, the corresponding letter may be presented to the user (e.g., via voice prompt).
Typically in these approaches, the iteration through characters starts with the first character of the group. For example, if the "2" key is pressed, iteration starts at "A", and if the "3" key is pressed, iteration starts at "D". Accordingly, for at least two-thirds of the characters entered on the keypad, multiple key presses are required. It is well known that using this technique to enter entire words and sentences is a tedious, error-prone, and generally unpleasant experience for the user, resulting in very limited deployment of applications requiring text entry on devices using numeric keypads (e.g., telephones).
There is a need to provide an improved method for entering characters on a numeric keypad that overcomes these problems.